Naltrexone, a medication used to treat alcohol and opioid dependence, works by blocking the effects of opioids and reducing cravings for these specific drugs. Naltrexone is not an opioid itself and does not produce the pleasurable effects of opioids. Instead, it blocks the receptors in the brain activated by opioids, effectively making the drugs less pleasurable and less effective. This can help individuals dependent on opioids decrease their drug use and reduce their risk of overdose. Naltrexone is taken orally, typically once a day, and is often used with behavioral therapy and support. It is not a cure for opioid or alcohol dependence, but it can be a valuable tool in managing these conditions.